The right-hander, who posted a 6.75 ERA in six appearances (four starts) with the Nationals last season, will take the spot of fellow top prospect Reynaldo Lopez -- the other main part of the Adam Eaton trade that sent Giolito to the White Sox this offseason -- while Lopez is on the disabled list.
Giolito battled an up-and-down season with Triple-A Charlotte, but he did toss a no-hitter while going 6-10 with a 4.48 ERA in 24 starts. He was 3-1 with a 1.71 ERA over his past five starts. Giolito will be the second White Sox prospect in as many days to make his first start with the club after Carson Fulmer started the second half of Monday's doubleheader.
"It's a glimpse of what's to come," White Sox manager Rick Renteria said. "I think they should be excited. We're excited to finally get to have them here with us and start to see them a little bit more and we can start to gauge where we're at, where they are in their development. We look forward kind of starting to scratch the surface of what's coming in the future.
"You can start getting them acclimated to pitching at the Major League level and see how well they're working so they can gain some knowledge and use it toward the following season."
A big key for Giolio will be finding greater success with his fastball. In 2016, his 94-mph four-seamer yielded a .355 average, six homers and a .742 slugging percentage over 62 at-bats. That slugging percentage was tied for second among pitchers with at least 60 at-bats ending on four-seamers.
Gibson (6-10, 6.05 ERA), who will counter Giolito, has just one quality start in his past six outings and hasn't allowed fewer than three runs in a start since July 4 against the Angels. He's gone at least six innings in six of his 21 starts.
Three things to know about this game
• The White Sox may have limited production out of MLBPipeline.com top prospect and starting second baseman Yoan Moncada. Moncada started the first game in Monday's doubleheader and sat out the second game as he deals with shin splints in his right leg.
"Shin splints is an irritation tendon against bone; they get irritated, and it takes time," Renteria said. "They're treating it. There's a wrap on it that hopefully compresses it to minimize the discomfort. Most of it is just how much you can do while still dealing with a little bit of the pain."
• The Twins have been revitalized in the American League Wild Card race despite selling off starter Jaime Garcia and closer Brandon Kintzler before the July 31 non-waiver Trade Deadline. Minnesota has won 12 of its past 16 games, scoring more runs than any team in the AL since Aug. 6.
• Twins outfielder Byron Buxton is riding a career-best 12-game hitting streak. He has hit .333 with four homers in August.